# 再帰、Dict
import sys
from collections import defaultdict 
from bisect import bisect_left
sys.setrecursionlimit(10**6)

n = int(input())
f = list(map(int, input().split()))

c = defaultdict(list)
for i, x in enumerate(f):
    c[x].append(i)
    
def cnt(x, l, r):
    return bisect_left(c[x], r) - bisect_left(c[x], l)

def calc(l, r):
    d = r - l
    nl = l
    nr = r - 1
    m = -1
    while nl <= nr:
        if cnt(f[nl], l, r) == 1:
            m = nl
            break
        if cnt(f[nr], l, r) == 1:
            m = nr
            break
        nl += 1
        nr -= 1
    
    if m == -1:
        return 0
    return calc(l, m) ^ calc(m+1, r) ^ 1


print("Alice" if calc(0, n) else "Bob")